Wrench



Jan. 16, .1923. 1,442,351.

W. A. MARTIN.

WRENCH! man Dam, 1921.

i3 '20 a ll 10 WMQU. 0 7 w INVENTOR W BY ATTO RN EY WITNESS:

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"WILLIAIME A. MAE/TIN, OF CANDQ, NORTH DAKOTA.

WRENCH.

Application filed December 3; 1921. Serial No. 519,697.

To all iii/1.02M it wuty camera:

Be it known that l, l VILLIAM A. MARTIN, a citizen of the United States, residing at Cando, in the county of Towner and State of North Dakota, have invented new and useful Improvements in Wrenches, of which the following is a specification.

This invention relates to wrenches, and has particular application to that class of wrenches wherein the jaws are movable toward and away from each other, and have their gripping action increased with a cor responding increase of pressure upon the handle of the wrench, the wrench being constructed to possess maximum strength and which is particularly useful in heavy work.

One of the chief objects of the present in vention, is to construct a wrench of the above mentioned character, eliminating the many pins, and slots embodied in wrenches with which i sin familiar, and which only tends to weaken the wrench in its entirety, making the wrench unsuitable for any work in that the pins and slots incident to wear become weak and frequently break.

Another object of importance resides in providing a wrench of the class in question, wherein the handle and the adjacent movable aw are provided with cooperating cam surfaces which are so designed, that they at all times contact at a point in align with the pivotal connection between the handle and the shank of the other jaw, which not only forms self locking wrench, but one that irrespective of the size of the object placed between the aws, maintains a pressure at all times on center.

A further object of the invention resides in providing a novel connection between the handle and the adjacent movable jaw to retard the movement of this jaw toward and away from the other aw which has its pivotal connection with the handle of the wrench, the construction being such that the maximum pressure is at all times worn by the pivot between the handle and the latter mentioned aw, and which pivot is made strong as any part of the wrench.

The nature and advantages of the invention will be better understood when the following detail description is read in connection with the accompanying drawing, the invention residing in the construction,

' combination and arrangement of parts as claimed.

In the drawing forming part of this application like numerals of reference indithe handle and the center of the jaws, which line is shown as intersecting; the point of con tact between the cooperating cam surfaces.

Figure 2 is a fragmentary longitudinal sectional view.

Figure 3 is a sectional view tel-zen on line 33 of Figure 1.

Figure 4 is a detail view of the lowermost movable jaw.

Figure 5 is a fragmentary view of a modified form of the invention.

Referring to the drawings in detail, 10

indicates the handle of the wrench which is bifurcated as at 11, and received by this hifureation 15 the shank 1910f the outermost aw 13. The separated portions 14 defined by the bifurcation of the handle, are designed to form cam like surfaces 15 which cooperate with similar surfaces 16 formed on the lowermost jaw 16. This jaw is as shown slidably mounted upon the shank 12 of the outermost 13. The gripping, faces of the respective jaws are equipped with teeth 18, the teeth for the jaw 17 being formed on a plate 19, the latter having: a dove tail d ext nsion 20 which is slidably fitted in a suitable groove or slot from one side of the jaw 17. A set screw or the like 22 holds this blade in position at a point which is subjected to little or no s. whatever. This minimizes the possibility of the blade being; broken when subjected to a heavy pull or strain. should the sot screw be arranged at any point in the area of the blac e. The jaw 17 is formed with an extension. 23 arranged in parallelism with the shank 12 of the movable jaw 13, this (31(- tensiou being also received between the separated portions defined by the bifurcation of the handle 10. The confronting; or adjz1- cent faces of these separated portions are formed with grooves 24L JFllltll receive the terminals of a pin passed through the extension 23, this pin moving in said grooves to retard the movement of the jaw 17 toward and. away from the outermost jaw 13 as will be readily understood. This pin however is subjected to very little or no strain at all, the maximum strain or pressure is at all times borne by the pivot 26 which associates the shank 19. with the handle 10. It to be understood that this pivot 26 is to be made of the proper material and proper size to aiford the wrench in its entirety maximum strength, which fact coupled with the general construction makes the wrench particularly advantageous for use in heavy work.

As hereinabove stated, one of the chief objects of this invention resides in the fact that no matter what size the object is that is placed between the jaws of the wrench, the

pressure exerted on said jaws is directly on center, or in other words on a straight line from the center of said aws to the pivot 26 which associates the handle with the shank of the outer aw 13. The particular configuration of the cam like surfaces 15 and 16 respectively, is such that a direct line drawn from the pivot 26 to the center of the aws will at all times intersect the point of contact between these cam like surfaces irrespective of the position of the jaws, thus maintaining a maximum pressure upon the center irrespective of the size of the object placed between the jaws, thereby providing in a sense a self-locking wrench, wherein the parts will remain in the position given until released by a reverse pressure upon the handle. The wrench embodies but few parts which are so compactly arranged, as to afford the wrench the maximum strength and rigidity. Manifestly, by reason of the construction and arrangement of parts as described, a much greater pressure or force can be obtained with the same amount of levelage, as compared with wrenches of the same size and weight, because the power used is always in a straight or direct line on center from the pivotal connection between the handle and the shank 11, thus placing the power pressure directly against thehigh pressure point of the object positioned between the jaws.

In Figure 5, I have illustrated a modified form of the invention wherein 10 indicates the handle which is pivotally connected as at 11. to the shank 12 of the outermost jaw 13, the outer end of the handle being formed to provide a cam like surface 15 as shown. The jaw 16 is slidably mounted upon the shank l2 and is formed to provide a cam like surface 17 which cooperates with the cam like surface 15 so that the pressure exerted on the gripping jaws is directly on center, or in other words, on a straight line from the center of the jaws to the pivot 11, thereby obtaining a very effective purchase upon the object placed between the jaws. This form of the invention is distinguished from the preferred form in that the eurva ture of the cam 17 is different from the curvature of the cam 16 formed on the sliding aw, and is designed to receive the cam like surface 15 of the handle of the wrench.

While it is believed that from the foregoing description, the nature and advantages of the invention will be readily apparent, I desire to have it understood that I do not limit myself to what is herein shown and described, and that such changes may be resorted to when desired as fall within the scope of what is claimed' What I claim is:

A wrench of the character described coinprisinga handle having a bifurcated curred end portion provided with slots on its opposed faces, a stationary jaw provided with a shank extending into the bifurcated end portion and pivoted therein in line with the center of the handle, a second jaw provided with an aperture receiving said shank and having a convex'surface corresponding with the curved surface of the handle the two surfaces contacting at a point in line with the center of the jaws and the pivot point of said stationary jaw, a shank extending from the movable jaw slidabl y mounted in the slot of the bifurcated end of the handle parallel to and contiguous with the shank of the stationary jaw at all times.

In testimony whereof I aflix my signature.

WILLIAM A. MARTIN. 

